Challenges of aligning district heating structures with climate goals across China's provinces.

Cost-effective decarbonization and clean heating, the major end-use of energy in China, is an urgent scientific challenge. This study proposed a generalizable framework to quantify facility-level cost-effectiveness to assess the application scope and emission reduction potential of various strategies, while evaluating their provincial compatibility with carbon neutrality goals. Our findings indicate that China's district heating system emitted 7.5 × 105 tons of SO2, 7.7 × 105 tons of NOx, 4.1 × 105 tons of PM2.5, and 1.2 × 109 tons of CO2 in 2020. Among these, 15,429 coal-fired industrial boilers (CFIBs) contributed 30 % of CO2 and 46 %-65 % of air pollutants, while 5581 combined heat and power plants (CHPs) accounted for 57 % of CO2 and 35 %-41 % of air pollutants. The 15 km heating pipeline network from CHPs currently covers 53 % of residential areas, leaving only 2890 CFIBs eligible for dismantling and connected to the grid. This limitation has driven most CFIBs to switch to biomass-fired boilers, especially in biomass-rich regions such as North and Northeast China. Furthermore, through scenario analysis, we found that most provinces will still face significant challenges in meeting growing heating demands under the current heating structure adjustments. This underscores the necessity need to delay CHPs retirements, expand heating networks to 50 km, and advance heat pump and energy storage technologies.